BIOL 112 1st Edition Lecture 18 Outline of Last Lecture I Blood Vessels as Tubes II Lymphatic System III Human Circulation Map IV Pumping Function of Heart V Fetal Circulation Outline of Current Lecture VI Shift at Birth VII Pathologies Defects VIII Blood Current Lecture I Shift at Birth At birth the lungs inflate and vascular flow through the lungs increase several folds in a few seconds Blood pressure in the pulmonary circuit drops drastically Consequences Foramen ovale snaps shut blood no longer flows between the atria Ductus arteriosus pinches shut blood flow between pulmonary artery and aorta no longer possible Microcirculation in placenta shuts down so eventually dies and falls of These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute II Pathologies Defects Patent Ductus Arteriosus seen in about 8 1000 births ductus doesn t close Blood in aorta moves into pulmonary artery instead Aorta can lose 50 75 of blood volume normally sent to systemic circulation This does NOT produce cyanosis the baby does not turn blue Heart has to work 2 4 times harder just for normal circulation heart and lungs carry excessive load and are progressively worn out Life expectancy is shorter 20 40 years Characteristic sound in chest machinery murmur buzzing of blood moving through ductus Sometimes self correcting occurs in the first few months but a surgical fix is simple Tetralogy of Fallot Fortunately rare 5 10 000 births heart severely malformed opening of aorta too far to the right septum between ventricles not complete the pulmonary artery is too small and the right ventricle walls too thick Blood doesn t get enough Oxygen takes on a purplish cast instead of a bright red Blueish color to skin cyanosis blue baby Trying to run mammalian metabolism on basically a frog reptile heart Untreated life expectancy is 1 10 years old Correction is not simple Must surgically reconstruct heart reposition of pulmonary and aortal openings and build septum If successful 5 success rate life expectancy increases 50 years with complications for the rest of life III Blood Plasma Matrix 55 60 of volume Extremely complex solution 90 water 1 3 nutrients sugars amino acids lipids 0 9 electrolytes 7 9 proteins blood clotting proteins immune proteins Plasma has an unusual feature it can quickly convert from liquid to solid it can clot Clotting involves a complex chain reaction of various protein components of plasma thromboplastins which is started by exposure of plasma to either collagen or substances released by injured cells Active fibrin is a sticky fibrous protein that forms elaborate meshworks of materials a clot Plasma clotting proteins serum Blood Cells 40 of total blood volume most of these cells are produced from stem cells in bone marrow Erythrocytes Red blood cells account for 99 9 of all cells 0 0077 mm in diameter Contain highly condensed array of hemoglobin Cells have 120 day life span when old they are eaten by phagocytic cells in liver and spleen Leukocytes White blood cells don t carry the hemoglobin account for 0 1 of all cells 5 000 10 000 mm 3 Most are involved in body defenses against diseases several types with different functions Thrombocytes Platelets 250 400 x 10 3 mm 3 very small cells very fragile can initiate the clotting reaction formed in bone marrow from megakaryotcytes Diapedesis Extravasation Basis for inflammatory response